Doors can be divided into two main types: Interior and Exterior. While the style and the look may be the similar, the functions of the two are drastically different. Similar to windows and walls, exterior doors must be durable and functional, safeguarding the indoor environment from external elements such as sun, wind, water, fire and forced entry. Well designed, manufactured and installed exterior doors work together harmoniously, by both looks and functions, with the rest of the building's structure and systems. Building Science recognizes the central role Door Systems play in providing indoor occupants the desired comfort and security.

Of course, an entry door is an exterior door and a gateway to one’s indoor space such as a home; the door's design, both in terms of material options and style, are the guest's first impression to an indoor space. Most common doors can be opened inwardly, outwardly or by sliding. Safety and regulations including escape and fire are important factors in choosing a particular door, material and style. Furthermore, in recent years, higher thermal performance requirements have been or will be enacted in many cities’ building codes to help lower the overall building energy consumption, while sustaining and improving indoor comfort. Some interior doors may require similar sound and heat barrier functions as an exterior door for a specific room. Some door styles such as Lift and Slide Doors and French Doors have glazing and aluminum cladding applied, closely related to the window systems in terms of their design and function principles, components, functions and manufacturing processes. In this Knowledge section, several major door styles are used as examples to illustrate door components, their functions and contributions to an overall door design and performance to achieve a desirable level of comfort and protection.

Short Reference Video: Door Section, Gasket Scissors, typical roll of Gasket.

At Rangate, our focus is on laminated solid wood doors. Compared to other materials used to make doors like steel or fiberglass, wood has resists conducting heat, minimizing heat transfer from one side of the door to another. Hot summer temperatures stay out, and in winter, less heating escapes through a wooden door. Some innovative doors even incorporate higher insulating materials, such as cork and Accoya® in their designs. These laminated wood doors can be produced with insulated cores to further provide excellent comfort and lower indoor energy consumption. It's not just us who think so- wooden doors are growing in demand, thanks to their energy-saving properties and sustainable sourcing. Research has shown how wood furniture and indoor plants have a positive on students’ behaviors and their learning abilities. Recently publications such as ones published by FPInnvoations also indicate the health benefits of using wood as a material in our work, live, and play environments:

• Wood as Restorative Material in Healthcare Environment [PDF, 486kb]
• Wood and Human Health Series

These FPInnovations studies provide evidence that we're all “healthier, happier, and more productive when connected with nature” through natural building materials like wood.

Aluminum cladding can be applied to certain wooden door designs to match the building's decor, and provide a layer of protection to the wooden parts. In the industry, this is commonly called a wood-ALU door system. Aluminum is highly thermally conductive, but fortunately, there are already proven cladding application systems that break the heat transfer between wood and ALU while introducing water drainage and drying opportunities. This gives the building the sleek look of aluminum, with the performance power of wood underneath.

One of the most common areas of confusion in getting started building doors is the terminology. There are several interchangeable terms for door joinery that you might hear. While we typically use "Mortise and Tenon" to refer to this style of joinery, there are some equivalent terms you might run into. Sometimes terms from different pairs will be mixed and matched, making getting up to speed even more confusing. Let's break down some of the terms you might encounter.

Tongue and Groove: This is another term for for mortise and tenon, where the Groove is another word for mortise, and Tongue is another word for tenon.


Profile and Counterprofile: The counterprofile is the tenoned end, also sometimes called the male piece. The profile is the mortised section, which might be referred to as the female component. You might also hear scribe to mean the profile (this is often used in Europe).


Cope and Stick: The coping cut is the end cut, akin to tenoning, while the sticking cut refers to cutting the profile.


Stile and Rail: The stiles are the vertical pieces in a door construction, while rails are horizontal. The very bottom piece can also be known as the kick.


Panel: Panels are what are held in between stiles and rails. A floating panel is set in a way which allows the wood to naturally expand and contract with the passing of seasons in a way that won't warp or exert force on the frame of the door.


Lites: Lites are panes of glass set into the door. True Divided Lites are individual glass panes set within a door separately. Simulated Divided Lites have can have the appearance of dividers externally, but are internally all the same pane of glass. Both approaches have strengths and challenges; true divided lites are more labor intensive to create and can create thermal performance challenges for exterior doors, while simulated divided lites require the entire glass pane to be replaced if any one part of the glass is damaged.

To illustrate an example of energy saving with a better thermally performing door, let’s use a reference list of thermal resistance properties, or R-Values.

Ready to crunch the numbers? A small example can illustrate what a big difference a better-performing door can make to the interior space. Let's imagine a wall assembly with a thermal resistance value of R-13.31, set with a flush wood 1-3/4” thick door with a hollow core, with an R-value of 2.17.

Let’s assume, in our example, the wall is 20’x15, and has just one 5’x7’ door. After the calculations, the wall’s effective R-value with this door is about R-8.3. While the door is only 12% of the total wall area, it loses 45% of its heating energy, due to its thermal inefficiency compared to the wall. Now let’s say we swap out to a flush wood 2-1/4” solid core door with a higher performance value of R-3.7. The wall’s effective R-value of this wall now becomes R-10.2, a 23% improvement. This translates to a heating energy savings of 255 kWh per year in San Francisco, CA or 449 kWh in Québec City, QC. The installation details of a thicker door in an existing wall will have additional impact on these figures, which can be detailed and optimized by a professional. Nonetheless, in our example, a thicker door with additional insulation properties in general will yield energy consumption savings and, make the interior space more comfortable- cooler when it's hot, warmer when it's cold.

Building a door that looks beautiful, performs well, and stands the test of time starts with the right plan. Before the first cut, success begins in the design office. Product manufacturing planning should be strategically integrated into the product design phase, especially if the product includes a cladding system.

Wood window and door manufacturing planning can be broken down into a few tasks and milestones so that all the components of the designs are understood, planned, and optimized for a sound business investment. Often, even highly customized designs will still use some standard supplies and processing methods. Planning design and production together early will incorporate past experience upfront, limit trial and error and optimize product costs - a recipe for a successful business.

Incorporate your designs and potential product lines with your production plans early to improve your production and business success rate. After all, we want our door and window systems to work optimally per design with all their components, and function flawlessly when integrated into a building enclosure. The Door Quick Start section may provide a few new insights and considerations for design and production.

Please feel free to explore the door styles, components, their functions, manufacturing processes, performance evaluations, and more building science facts and studies throughout our website. We're committed to door design, quality, and performance. Our business is to grow the availability and affordability of windows and doors which look and function better, conserve more energy, and last longer than what's currently available. If you are thinking of becoming or already are a door manufacturer, check out the Quick Start section to get some kick-starting business development ideas.

We also welcome YOUR knowledge. Get connected. Please share any thoughts on our content, or showcase your projects here with us.